In the old days, if my players, or when I played in other games, were in a large scaled battle, we would usually fight a couple of encounters within the battle and then the DM would narrate what happened in the overall battle. That will still work with 4e, but I want to make large battles different from just regular encounters so I made the following rules using the Challenge System in 4e. I like this because it makes players think more and roleplay instead of just hack and slash.
See what you think.
Cheers.
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Mass Combat in 4e - I’ve decided to use Skill Challenge for small or large cinematic battles.
This way, depending on the battle situation and relative size or composition, the DM can set a difficulty level and complexity level. For the difficulty level, use average PC level at Hard level for most battles. (Of course, the specific DC should really depend on how hard DM feels the action should be). For complexity level, I suggest using the number that gives each PC in the party 2 chances to perform in a skirmish, 3 chances in a battle and 4 chances in a major war.
In battle, all PCs must say what they will do to help their side. This can include attack (use attack bonus as modifier) or defend (use bonus to AC as modifier), use a skill, etc. Really good ideas that seem consistent with character concept will gain +2 bonus.
If a PC fails a Skill Check, the PC will take battle damage according to how large the conflict is. (See table below taken from DMG). If a PC goes down, other PCs can try to heal just like in combat or Clerics, Paladins, or other PCs with healing powers can use their powers instead of taking a Skill Check turn.
DIFFICULTY CLASS AND DAMAGE BY LEVEL
Difficulty Class (DC) Values Battle Damage per Failure
Level Moderate Hard Skirmish Battle Major War
1st – 3rd 10 15 3d6+3 2d10+3 3d8+3
4th – 6th 12 17 3d6+4 3d8+4 3d10+4
7th – 9th 14 19 3d8+5 3d10+5 4d8+5
10th – 12th 16 21 3d8+5 4d8+5 4d10+5
13th – 15th 18 23 3d10+6 4d8+6 4d10+6
16th – 18th 20 25 3d10+6 4d10+7 4d12+7
19th – 21st 22 27 4d8+7 4d10+7 4d12+7
22nd – 24th 24 29 4d8+8 4d12+8 5d10+8
25th – 27th 26 31 4d19+9 5d10+9 5d12+9
28th – 30th 28 33 4d10+9 5d10+9 5d12+9
COMPLEXITIES OF SKILL CHALLENGES
Complexity Successes Failures
1 3 3
2 6 3
3 8 3
4 10 3
5 12 3
If the party incurs 3 failures, before they succeed, they must fall back and regroup. This resets the Skill Challenge, but it also causes each character to take battle damage. In this case, the enemy forces are pushing the PCs and their forces back.